Treatment algorithm
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vitamin C replacement
No apparent consensus exists in the medical literature for the exact amount of vitamin C supplementation for optimal scurvy treatment. Several case series with successful outcomes have been reported with <10 mg/day. Higher doses appear to improve signs and symptoms of scurvy more rapidly, as body stores are replenished faster.[2]
Given the risk of worsening symptoms or life-threatening events, vitamin C replacement therapy should begin as soon as possible after signs and symptoms are identified.
Thus, best evidence suggests at least 300-500 mg/day of vitamin C (ascorbic acid) for adults. The optimum dose for children is not determined, but should be at least the recommended daily intake. The maximum daily doses for sub-groups are outlined in the accompanying table of recommended daily intake to prevent vitamin C deficiency, and are based on actual and theoretical adverse risks as identified in experimental models and human trials of megadose vitamin C for various conditions.
[Figure caption and citation for the preceding image starts]: Recommended daily quantity of vitamin C to prevent deficiency. The appropriate RDA has been disputed in several large reviews. These guidelines are drawn from the most recent published large consensus of appropriate intake based on data from historical, biological, epidemiological, and intervention studiesFrom: Panel on Dietary Antioxidants and Related Compounds, Subcommittees on Upper Reference Levels of Nutrients and Interpretation and Uses of DRIs, Standing Committee on the Scientific Evaluation of Dietary Reference Intakes, Food and Nutrition Board, Institute of Medicine. Chapter 5: vitamin C. In: Food and Nutrition Board, Institute of Medicine's Dietary reference intakes for vitamin C, vitamin E, selenium, and carotenoids. Washington DC: National Academy Press; 2000: 95-185 [Citation ends].
For hospitalised and critically ill patients, no apparent consensus exists in the medical literature for the exact amount of vitamin C supplementation to prevent and treat vitamin C deficiency. However, European Society for Clinical Nutrition and Metabolism recommends the following as a guide: daily recommended dose for adults receiving parenteral nutrition is 100-200 mg/day; daily recommended dose for adults with chronic oxidative stress is 200-500 mg/day; daily recommended dose for adults during critical illness or continuous renal replacement therapy is 2-3 g/day (given intravenously).[62] However, recent studies have shown that adjunctive vitamin C therapy has not been shown to improve outcomes and may even worsen outcomes in patients with acute respiratory distress syndrome or sepsis, respectively.[51][71] Therefore, supplementation of vitamin C is not recommended beyond the recommended daily intake in the setting of critical illness.
After at least 2 weeks of vitamin C replacement therapy, the general approach to prevention of vitamin C deficiency should be assumed. Chronic supplementation with vitamin C may be indicated in some people.
The suggested doses are likely quantities required to prevent myriad chronic diseases potentially influenced by vitamin C levels. Population-based surveys suggest that the diets of most people in the US and Canada meet the recommended daily intake of vitamin C without the need for daily supplementation.
Areas with known low vitamin C intake include populations with cereal-, millet-, or rice-based diets, particularly in Africa, India, east Pakistan, Afghanistan, some areas of Latin America, and the near East.[1] In these and other susceptible populations, greater attention to dietary history may be required to meet daily nutritional needs.
Primary options
ascorbic acid: children and adults: individualise dose according to clinical presentation and patient factors
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Please note that formulations/routes and doses may differ between drug names and brands, drug formularies, or locations. Treatment recommendations are specific to patient groups. See disclaimer
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